Q. Show the Features of Hyper-threading?

The significant characteristics of hyper threading are:

i) Improved response time and reaction, as well as increased number of users a server can support.

ii) Improved support for multi-threaded code, allowing multiple threads to run concurrently.

According to Intel, first implementation only used an added 5% of die area over 'normal' processor thus far yielded performance improvements of 15-30%. Intel claims up to a 30% speed improvement with respect to otherwise identical, non-SMT Pentium 4. But performance improvement is very application dependent and a number of programs in fact slow down slightly whenever HTT is turned on. 

This is due to replay system of Pentium 4 tying up valuable execution resources thus starving for other thread. Though any performance degradation is unique to Pentium 4 (Because of several architectural nuances) and isn't characteristic of concurrent multithreading in general.